By Christian Hinke

Digital photonic production enables us to fabricate almost any component or product directly from digital data. Experts characterize the photon or the laser as the only tool that “works” as quickly as a computer “thinks.” An office laser printer functions according to this principle and reveals what will be possible in future manufacturing with high energy lasers – when the fundamental interactions between material, light and photonic process chains have been understood and, based on this knowledge, digital photonic production systems have been put into practice.

Laser based additive manufacturing or 3D printing is the most prominent example of this principle. Actually 3D printing receives some recognition from general media and was even mentioned by President Obama in his recent State of the Union address. Technologies that were developed more than 10 years ago for rapid prototyping are now evolving into rapid manufacturing technologies. Currently, laser based additive manufacturing technologies are being tested for serial production in pilot plants in the automobile and aerospace industry.

Fig. 1: Selective laser melting (SLM) for serial metal components, Fraunhofer ILT

Fig. 1: Selective laser melting (SLM) for serial metal components, Fraunhofer ILT

Fig. 2: Lightweight, topology-optomized automotive component, Fraunhofer ILT, Volker Lannert

Fig. 2: Lightweight, topology-optomized automotive component, Fraunhofer ILT, Volker Lannert

Selective Laser Melting (SLM), sometimes referred to by the terms Direct Metal Laser Sintering (DMLS) or LaserCusing® is one of the most promising technologies in additive manufacturing. The SLM technology developed by the Fraunhofer ILT is an additive manufacturing process by which metallic components are produced directly from 3D digital data (see Figure 1). It enables geometries of nearly unlimited complexity to be manufactured, as the component is built up layer by layer. This results in a new design paradigm: “Complexity for free.” So additive manufacturing enables new ways of product design, only determined by functional requirements without any manufacturing restrictions (see Figure 2 and Figure 3).

Fig. 3: Lightweight aerospace component with lattice structure, Fraunhofer ILT

Fig. 3: Lightweight aerospace component with lattice structure, Fraunhofer ILT

Digital Photonic Production goes far beyond laser based additive manufacturing. New ultra-short pulsed lasers enable, for example, very fast ablation, nearly independent of the material being processed (see Figure 4). This way, smallest functional structures can be fabricated all the way down into nanometer range. Digital Photonic Production also enables the selective modification of material. For example, molds can be polished with laser radiation, or 3D microfluidic systems for medical applications can be “written” directly from digital data. These applications show the potential of Digital Photonic Production and are the first examples of the vision: “From Bits to Photons to Atoms.”

Fig. 4: High-performance ablation of metal with ultra-short pulsed lasers

Fig. 4: High-performance ablation of metal with ultra-short pulsed lasers

Some experts see a new industrial revolution enabled by these new manufacturing technologies and especially by the direct production from digital data. Essentially, the revolutionary potential of Digital Photonic Production is based on a fundamentally different relation of cost, lot size and product complexity compared to conventional manufacturing processes (see Figure 5). There is no increase of costs for small lot sizes (in contrast to e.g., mold-based technologies) and no increase of costs for product complexity (in contrast to e.g., subtractive technologies).

The new production paradigms “individualization for free” and “complexity for free” will result in new innovative products and new business models. Internet platforms like shapeways.com, ponoko.com, imaterialise.com or thingiverse.com are just the beginning and show the economic potential of these new paradigms.

Fig. 5: Digital photonic production: "individualization for free" and "complexity for free," Fraunhofer ILT

Fig. 5: Digital photonic production: “individualization for free” and “complexity for free,” Fraunhofer ILT

In principle, the advantages of photon-based manufacturing have been known for a long time, but only practically used in niche areas, such as medical implants. The cost per piece using laser based manufacturing processes were independent of lot size and complexity, but until now was still quite high.

This has changed significantly: laser processes have become much quicker and less costly. At the same time, the costs for beam sources and machine costs have sunk considerably. For example, the build rate of SLM has increased by a factor of 10. Simultaneously, ultra-short pulsed lasers are now commercially available in the kilowatt range, which raises the ablation rate of 3D laser structuring by a factor of 10 as well.

Laser based additive manufacturing processes, which formerly had been used in some niche applications, will now become attractive for series production when small and medium lot sizes are required. Thus, production technology faces similarly great changes as it did in the last 10 years when 2D laser beam cutting was developed and introduced for the processing of sheet metal. When series-ready additive manufacturing processes or 3D ablation processes become available, direct production of any kind of component will become possible from digital data. Hence, laser based manufacturing processes have evolved into Digital Photonic Production.

In order to exploit the full potential of Digital Photonic Production, process chains have to be viewed in an integrated way. Industrial process chains have to be redesigned, reaching from new up- and downstream manufacturing steps, over product design, all the way to completely new business models such as mass customization or open innovation.

The new research campus “Digital Photonic Production” in Aachen, funded by the German Federal Ministry of Education and Research (BMBF), is dedicated to exactly this integrated approach. More than 30 partners from science and industry will work together under one roof on fundamental research topics. But beyond the trend-setting topic, the even more important point is the long-term strategic co-operation of all partners in one place.

Christian Hinke is the RWTH Aachen University Chair for Laser Technology at Fraunhofer ILT.